Audi S4 Power Seat Failure: Common Wiring Issue Fix

I had a very similar issue with my 2017 Audi S5 last winter. With some experience working on basic car maintenance, I initially thought it was just a blown fuse, but it turned out to be more complex. The passenger seat was completely unresponsive, and the seat switch showed no signs of life. After checking the fuse box myself, I took it to my regular workshop. They diagnosed a severe battery drain that was affecting the entire seat harness system. The car seat electrical components were drawing excessive power, which eventually led to connection issues in the seat control module. The repair involved replacing some damaged wiring in the automotive seat harness and addressing the battery issue. Total cost was 290 Euro, including diagnostic work. The shop completed everything in about 4 hours. Before suggesting specific solutions, could you share: Have you checked the fuse box? Does your driver seat still work normally? Are there any other electrical issues in the car? When did you first notice the car seats malfunctioning? This information would help determine if you are experiencing the same underlying issue I had with my vehicle.

Last service was completed at 81743 KM. Yes, I checked the fuse box first thing and all fuses are intact. The driver power seats work perfectly fine with no issues. No other electrical problems noticed in the car. The passenger seat suddenly stopped working while my friend was adjusting it. The seat motor makes no sound when pressing the controls. Given these symptoms, it does sound similar to the wiring issue you described. Will have it checked by a professional since it seems more complex than a simple fuse replacement. Thanks for sharing your repair experience and costs, helps set expectations for the shop visit.

Based on those details, it definitely matches the symptoms I experienced with my S5. Since the seat motor isnt making any sound and your fuses are good, this reinforces my initial suspicion about the seat harness wiring being the core issue. In my case, the complete silence from the electric seat mechanisms was a telltale sign of a wiring fault rather than a faulty seat motor. One thing I learned during my repair, these seat systems have multiple connection points that can deteriorate over time, especially with frequent seat adjustments. The repair shop found that in addition to the wiring issue, there was minor corrosion on some of the seat adjustment connectors. While they were fixing the main harness, they also cleaned these connections which helped prevent future issues. Since your mileage is similar to what mine was when the problem occurred (around 80000 km), and the symptoms match exactly, you are likely looking at a comparable repair cost, though parts prices may have changed since my repair last year. Quick tip: When you take it in, ask them to check the seat control module connections as well. In some cases, they can become loose without showing other electrical symptoms, and checking them during the harness repair doesnt add much to the labor time.

Thanks for detailing your similar experience with the S5. Your situation does sound nearly identical to mine, especially with the complete silence from the seat motor. After checking all the basics like fuses and seeing that only the passenger seat is affected, I am pretty convinced it is indeed a wiring harness issue as you described. The fact that your repair cost came to 290 Euro gives me a reasonable target to expect. Good point about having them check the seat control module connections while they are in there, will definitely mention that to save potential future headaches. Based on the symptoms and the similar mileage when your issue occurred, this does seem like a common failure point for these seat adjustment systems. Going to schedule the repair next week. Will make sure to have them thoroughly inspect the entire seat harness system and clean any corroded connectors they find. At least the driver seat is still working perfectly, so I can still use the car normally until then. Appreciate your detailed explanation of what to expect. Really helped narrow down the likely cause and set realistic repair cost expectations before heading to the shop.